Control device for motor that drives a vehicle

Abstract

A control device for a motor that drives a vehicle and controls the motor by controlling an inverter device that converts a direct voltage, supplied from a direct current source, into an alternating voltage to be supplied to the motor, the control device having a refrigerant temperature detector that detects a refrigerant temperature of a heat exchanger for heat exchange with the inverter device, and a torque restrictor that restricts an output torque of the motor when the inverter device is put in a predetermined state, wherein the torque restrictor changes restrictions on the output torque on the basis of the refrigerant temperature detected by the refrigerant temperature detector.

1. A control device for a motor that drives a vehicle and controls the motor by controlling an inverter device that converts a direct voltage, supplied from a direct current source, into an alternating voltage to be supplied to the motor, the control device comprising:
 a refrigerant temperature detector that detects a refrigerant temperature of a heat exchanger for heat exchange with the inverter device, and 
 a torque restrictor that restricts an output torque of the motor when the inverter device is put in a state of overheat, wherein the torque restrictor restricts the output torque to a calculated continuous operation enabling torque so that the output torque when the refrigerant temperature detected by the refrigerant temperature detector is high is lower as compared with the output torque when the refrigerant temperature is low. 
 
     
     
       2. The control device according to  claim 1 , wherein the torque restrictor causes the motor to operate continuously irrespective of a state of the inverter device when a torque command value of the motor is smaller than the continuous operation enabling torque that is calculated on the basis of the refrigerant temperature and affords continuously operating the motor. 
     
     
       3. The control device according to  claim 2 , further comprising a stall state detector that detects a stall state of the vehicle, wherein the torque restrictor has a storage device that stores at least one of a predetermined operation expression and a map found to be representative of the correlation among the refrigerant temperature, a torque command value, and time, during which an electric current can be carried to the motor, and
 a current-carrying enabling time calculation element that calculates a current-carrying enabling time from the at least one of the predetermined operation expression and the map on the basis of a refrigerant temperature and a torque command value, wherein when the stall state detector detects the stall state, the output torque is restricted after a current-carrying enabling time calculated by the current-carrying enabling time calculation element has elapsed. 
 
     
     
       4. The control device according to  claim 1 , further comprising a stall state detector that detects a stall state of the vehicle, wherein the torque restrictor comprises a storage device that stores at least one of a predetermined operation expression and a map found to be representative of the correlation among the refrigerant temperature, a torque command value, and time, during which an electric current can be carried to the motor, and
 a current-carrying enabling time calculation element that calculates a current-carrying enabling time from the at least one of the predetermined operation expression and the map on the basis of a refrigerant temperature and a torque command value, wherein when the stall state detector detects the stall state, the output torque is restricted after a current-carrying enabling time calculated by the current-carrying enabling time calculation element has elapsed. 
 
     
     
       5. A control device for a motor that drives a vehicle and for controlling the motor by controlling an inverter device that converts a direct voltage supplied from a direct current source, into an alternating voltage to be supplied to the motor, the control device comprising:
 refrigerant temperature detection means for detecting a refrigerant temperature of a heat exchanger for heat exchange with the inverter device, and 
 torque restriction means for restricting an output torque of the motor when the inverter device is put in a state of overheat, wherein the torque restriction means restricts the output torque to a calculated continuous operation enabling torque so that the output torque when the refrigerant temperature detected by the refrigerant temperature detection means is high is lower as compared with the output torque when the refrigerant is low. 
 
     
     
       6. The control device according to  claim 5 , wherein the torque restriction means causes the motor to operate continuously irrespective of a state of the inverter device when a torque command value of the motor is smaller than the continuous operation enabling torque that is calculated on the basis of the refrigerant temperature and affords continuously operating the motor. 
     
     
       7. The control device according to  claim 6 , further comprising stall state detection means for detecting a stall state of the vehicle, wherein the torque restriction means comprises storage means that stores at least one of a predetermined operation expression and a map and found to be representative of the correlation among the refrigerant temperature, a torque command value, and time, during which an electric current can be carried to the motor, and
 current-carrying enabling time calculation means for calculating a current-carrying enabling time from the at least one of the predetermined operation expression and the map on the basis of a refrigerant temperature and a torque command value, wherein when the stall state detection means detects the stall state, the output torque is restricted after a current-carrying enabling time calculated by the current-carrying enabling time calculation means has elapsed. 
 
     
     
       8. The control device according to  claim 5 , further comprising stall state detection means for detecting a stall state of the vehicle, wherein the torque restriction means comprises storage means for storing at least one of a predetermined operation expression and a map and found to be representative of the correlation among the refrigerant temperature, a torque command value, and time, during which an electric current can be carried to the motor, and
 current-carrying enabling time calculation means for calculating a current-carrying enabling time from the at least one of the predetermined operation expression or map on the basis of a refrigerant temperature and a torque command value, wherein when the stall state detection means detects the stall state, the output torque is restricted after a current-carrying enabling time calculated by the current-carrying enabling time calculation means has elapsed. 
 
     
     
       9. A method for control of a motor, that drives a vehicle, by controlling an inverter device that converts a direct voltage supplied from a direct current source, into an alternating voltage to be supplied to the motor, the method comprising:
 detecting a refrigerant temperature of a heat exchanger for heat exchange with the inverter device, and 
 restricting an output torque of the motor when the inverter device is put in a state of overheat, wherein the output torque is restricted to a calculated continuous operation enabling torque so that the output torque when the refrigerant temperature is high is lower as compared with the output torque when the refrigerant temperature is low. 
 
     
     
       10. The method according to  claim 9 , further comprising causing the motor to operate continuously irrespective of a state of the inverter device when a torque command value of the motor is smaller than the continuous operation enabling torque that is calculated on the basis of the refrigerant temperature and enables continuously operating the motor. 
     
     
       11. The method according to  claim 10 , further comprising:
 detecting a stall state of the vehicle; 
 storing at least one of a predetermined operation expression and a map found to be representative of the correlation among the refrigerant temperature, a torque command value, and time, during which an electric current can be carried to the motor; and 
 calculating a current-carrying enabling time from the at least one of the predetermined operation expression and the map on the basis of a refrigerant temperature and a torque command value, wherein when the stall state is detected, restricting the output torque after the current-carrying enabling time has elapsed. 
 
     
     
       12. The method according to  claim 9 , further comprising:
 detecting a stall state of the vehicle; 
 storing at least one of a predetermined operation expression and a map found to be representative of the correlation among the refrigerant temperature, a torque command value, and time, during which an electric current can be carried to the motor; and 
 calculating a current-carrying enabling time from the at least one of the predetermined operation expression and map on the basis of a refrigerant temperature and a torque command value, wherein when the stall state is detected, restricting the output torque after the current-carrying enabling time has elapsed.